Wireless communication devices, such as cellular telephones, mobile radio/telephones and portable radio/telephones, operate by sending a request for a wireless communication service to a communication resource controller. The request typically contains the requesting unit's individual identification code (ID), the type of service requested, and identity of a target unit, where the target unit may be a wireless communication unit or a wireline communication unit. The types of wireless services that may be requested include one-to-one communications (i.e., private calls), one-to-many communications (i.e., group or conference calls), data transmissions, and/or telephone interconnect calls (i.e., calling a wireline telephone user). For example, if the requesting unit desires to place a private call to another communication unit, the request would include the requesting unit's ID, the target unit's ID, and a private call request.
Upon receiving the request, a communication resource controller determines whether the requesting communication unit is authorized to access a wireless communication system and the requested service. If authorized, the communication resource controller interprets the service requested and identity of the target unit. Depending on the service requested and identity of the target unit, the communication resource controller attempts to provide the requested service by establishing a communication path between the requesting unit and the target unit. For example, if the requested service indicates a private call between two wireless communication units that are within the coverage area of the communication resource controller, the controller can establish the private call by allocating a wireless communication resource to the wireless communication units.
If, however, the requested service indicates a private call between a requesting unit in the wireless communication system and a target unit that is a wireline communication unit, the communication resource controller needs to establish a wireless path and a wireline path for the requested communication to occur. The communication resource controller establishes the wireless path as it would for a communication between two wireless communication units, but, to establish the wireline path, the communication resource controller must be coupled to some sort of public switching network, such as the public switch telephone network (PSTN). Once the wireless and wireline paths are established, the requested service may be executed.
To ensure that a wireless communication unit manufactured by XYZ corporation can communicate with a wireless communication unit manufactured by ABC corporation, standards have been, and are being, established. In essence, the standards dictate how wireless and/or wireline communications are to be established. For example, the European standard for cellular telephone communications is the global system for mobile communications (GSM) standard. Thus, manufacturers that want to sell wireless communication units throughout Europe must design their equipment to be compliant with the GSM standard.
In addition to complying with these standards, the manufacturer must also conform their product to governmental regulations and/or laws. For example, in the United States, the Federal Communications Commission (FCC) has proscribed certain frequency bands to be used for certain types of communications. For example, land mobile communications are given one frequency band, while cellular telephone communications, commercial radio transmissions, and television transmissions are each given a different band. In addition to national regulatory requirements, state or Federal laws may limit the practicality of such wireless communication units. For example, many European countries have made it illegal to use a hand operated cellular telephone while driving an automobile, thus requiring drivers to stop their vehicles to place a telephone call or have hands-free operation.
While complying with the standards and governmental regulations, manufacturers cannot lose sight of consumer needs and requirements. Consumers are demanding that their wireless communication units be lighter weight, have extended battery life, more features, and be smaller in size. For example, consumers are requiting their cellular telephones be able to transmit and receive facsimiles, to allow their personal computers to interface with a network, and to interface audio equipment such as a headset, compact disc players, etc.
To meet the regulatory requirements, cellular telephone manufacturers may utilize a three chip set such as AT&T's GSM hardware platform. This chip set allows cellular telephone manufacturers to perform the radio frequency (RF) function of a cellular telephone, the base band modem functions, and audio codec functions. While this chip set meets the regulatory requirements, it does not provide for efficient full duplex hands free operation. To provide hands free operation, manufacturers are required to include an additional digital signal processor (DSP), such as Motorola's DSP56001 or DSP56156, programmed to perform an echo cancellation algorithm.
As is generally understood, when additional integrated circuits (IC), or chips, are needed to perform functions, additional power is consumed, additional circuit board real estate is needed, and operating speeds are slowed as information is transported between the ICs. Thus, the manufacturer of cellular telephones must provide for four chips in the layout of the cellular telephone and limit the consumers' goal of lighter weight, smaller packages, and longer talk time.
An alternative to using the AT&T chip set is to use DSPs programmed to perform the various functions. While this will provide the needed functions, it has similar limitations as the AT&T chip set, in that many chips are needed to perform the desired functions, thus limiting the consumers' goals.
Therefore, a need exists for a method and apparatus that provides a single integrated circuit that performs the above-mentioned cellular telephone features while more readily accommodating the consumer requirements of lighter weight, smaller packages, and longer talk time.